Noel,If you will forgive me for hastily responding to just one observation in your response while working over the entire message, there is one thing I'd like to highlight as I found it interesting and I hope you will too.
Noel Chiappa wrote:
> My intuition says that as the degree of interconnection in the inter-AS
> cloud increases, then the BGP "amplification" of underlying events
> increases
Not just degree of interconnection; as I mentioned above, as the network
grows, the average path length grows, so intuitively (and maybe I'm wrong
here, but I think this is likely) there's a slow growth in the likelihood
that any particular connectivity change will impact any given path.
This is the comment I'd like to quickly respond toSince 1998 we have the Route-Views data, and it is possible to look at each individual route views peer as a data sequence that now spans a decade (Route-Views is truly a really valuable data resource - I'd suggest its far and above the best we have for this work! My profound thanks to the crew there for setting it upand running it!)
A set of observations across the entire route views history is graphed at http://www.potaroo.net/bgprpts/rva-index.html
Since 1998 the network was grown from 50,000 entries to 225,000 entries and advertised address space now spans 1.7 x 10**9 /32s, growing from 0.95 x 10**9 in 1998. The number of AS's in the network has grown from 3,000 to 26,000
BUT the average path length has remained pretty steady - most Route Views peers see the entire network at an average AS path length of around 3.4, and have done so since 1998.
(http://www.potaroo.net/bgprpts/bgp-average-aspath-length.png)i.e. as the network grows it gets more interconnected, and not longer and stringer. As the network grows, the density of interconnection increases. i.e we are seeing higher inter-connectivity levels, which I would see as one of the major factors that contribute to the BGP behaviours we see today.
I'll respond in some further length later Noel to your response, but I thought you'd be interested in this particular aspect of the last 10 years of growth of the Internet - that the "shape" of the Internet's growth over the past decade is not really an expanding sphere of relatively constant internal density, but its been more like a sphere of constant diameter with increasing internal density.
cheers, Geoff -- to unsubscribe send a message to rrg-request@psg.com with the word 'unsubscribe' in a single line as the message text body. archive: <http://psg.com/lists/rrg/> & ftp://psg.com/pub/lists/rrg